Memphis Grizzlies’ Nick Calathes suspended for failed drug test

Memphis Grizzlies guard Nick Calathes was suspended by the NBA on Friday for failing a drug test. The suspension is for 20 games.

The suspension starts immediately and will carry over to the 2014-15 season. Calathes tested positive for Tamoxifen. Tamoxifen blocks the effects of estrogen in the body and is used to treat breast cancer in men and women, according to the Mayo Clinic.

It can also reduce the side effects of steroids. Sources say Calathes was using an athletic supplement in which Tamoxifen is an ingredient, according to Yahoo Sports, which first reported the suspension.

The NBA isn’t the only sport where Tamoxifen is banned. It’s also on Major League Baseball’s and the International Olympic Committee’s banned substance list.

"I deeply regret my actions and apologize to my teammates and the organization for my poor judgment," Calathes told USA Today. "Let me be clear: I never took any medication whatsoever for a performance-enhancing reason. I don't agree with this outcome, and I will come back a better player and person when I return."

Calathes is filing a grievance on the suspension. In his test results, there is no evidence of testosterone or performance-enhancing drugs. This season, he has averaged 4.9 points and 2.9 assists during the regular season as a rookie, according to ESPN.

Veteran point guard Beno Udrih will fill in for Calathes. The Grizzlies finished the season as the seventh seed in the Western conference and will begin the playoffs on Saturday against the Oklahoma City Thunder.